What is the shrinkage uniformity of PVC shrink film related to?

The shrinkage uniformity of PVC shrink film is affected by many factors. The following are some main factors:

Quality of raw materials: The purity and particle size of PVC resin are key factors. Films made of high-purity PVC resin usually have better transparency and tensile properties, while different specifications of PVC resin will also affect the shrinkage performance and anti-aging properties of the film. Therefore, selecting the appropriate PVC resin is the key to improving membrane performance.

Types and amounts of fillers and additives: Common fillers such as calcium carbonate, talc, etc. can improve the processing performance of PVC resin and reduce costs. Auxiliaries include plasticizers, stabilizers, lubricants, etc., which can improve the processing performance, mechanical properties and aging resistance of the PVC film. Therefore, the selection and addition amount of fillers and additives also have an important impact on the shrinkage uniformity of the film.

Processing technology: Process parameters such as processing temperature, extrusion speed, and cooling speed need to be precisely controlled to ensure the thickness, uniformity, and shrinkage performance of the film. In addition, the selection of processing equipment is also critical, and different equipment may have different processing characteristics.

Heating temperature and heating time: The shrinkage of PVC shrink film is based on the characteristics of thermal shrinkage, so heating temperature and heating time have a direct impact on shrinkage uniformity. If the temperature is too high or too low, and the heating time is too long or too short, it may have a negative impact on the shrinkage uniformity of the film.

In order to obtain a PVC shrink film with uniform shrinkage, it is necessary to comprehensively consider and optimize many aspects such as raw material selection, filler and additive addition, processing technology, and heating conditions.